1. Field of the Invention
The present invention relates to a switch apparatus that is mainly provided at the lower part of a handle of an automobile to control, by the operation of a lever, the operation of a light, windshield wiper or the like.
2. Background Art
Recently, there have been more automobiles including a switch apparatus in which a lever switch provided at the lower part of a handle can be operated to control the operation of a turn signal, lighting of light, or the operation of a windshield wiper, for example.
FIG. 9 is a cross-sectional view of a conventional switch apparatus. FIG. 10 is an exploded perspective view of the conventional switch apparatus. In FIG. 9 and FIG. 10, lever switch 1 (hereinafter referred to as “switch 1”) includes substantially box-like case 2, left lever 3, and right lever 4. Levers 3 and 4 are attached to both ends of case 2 so as to be able to be pivoted with click feeling. Levers 3 and 4 are pivoted to electrically connect and disconnect switch contacts (not shown) in case 2.
Case 2 has at the substantial center a communication hole to provide cylinder section 5 that extends in the lower direction and that has a substantially circular cylinder shape.
Cylinder section 5 has, along the inner circumference at the root thereof, reception section 5A that is projected inwardly and that has a flat face shape. Reception section 5A has, at the lower face thereof, substantially rectangular engagement convex section 5B (hereinafter referred to as “section 5B”) that is projected in the lower direction.
Cylinder section 5 also has, at both sides thereof, slits to provide a plurality of lock pieces 5D and a plurality of elastic contact pieces 5E. Lock piece 5D has, at the inner side, lock section 5C that has an arm-like shape to be elastically deformed and that is convex. Lock piece 5D also has, at the outer side, retention section 5F that is convex. Elastic contact piece 5E has a projection section that has an arm-like shape to be elastically deformed and that has a hill-like shape at the entire outer face thereof in the longitudinal direction.
Metal columnar support 6 has a substantially circular cylinder shape and extends out of a vehicle body (not shown). Steering shaft 7 (hereinafter referred to as “shaft 7”) protruding to the upper part of columnar support 6 is inserted to columnar support 6 so as to be rotatable. Furthermore, an upper end of columnar support 6 works as abutting section 6C. Abutting section 6C has, at the outer circumference thereof, engagement concave section 6A (hereinafter referred to as “section 6A”) that has an inner width that is slightly larger than an outer width of section 5B. Section 6A is inserted to and engaged with section 5B to fix the rotation of case 2 to columnar support 6.
Abutting section 6C is abutted with section 5A. Furthermore, lock section 5C is engaged with concave locking section 6B at the outer circumference of columnar support 6. This allows case 2 to be locked to columnar support 6.
Ring 8 is made of highly elastic metal and has a strip-like shape. Ring 8 is provided between a lower face of case 2 at the outer circumference of cylinder section 5 and retention section 5F. Ring 8 presses lock piece 5D and elastic contact piece 5E from those outside. Switch 1 is attached to columnar support 6 while the rotation and up-and-down movement being regulated.
The switch apparatus thus structured has shaft 7 that is upwardly protruded. Shaft 7 is attached with a handle (not shown). A switch contact of switch 1 is connected, via a connector cable (not shown) or the like, to an electronic circuit (not shown) of the vehicle body.
When lever 3 is pivoted and operated in the structure as described above, switch contacts in case 2 are electrically connected and disconnected and an electric signal is transmitted via the connector cable to the electronic circuit of the vehicle body. Then, a turn signal representing right turning or left turning is lighted (not shown), for example.
Alternatively, when lever 4 is pivoted and operated, the rate at which the windshield wiper is operated is changed in accordance with the position at which lever 4 was operated (not shown).
The conventional switch apparatus as described above is disclosed, for example, in Japanese Laid-Open Utility Model Publication No. 6-45220, for example.
However, when an extremely high operation force or impact force is applied to levers 3 and 4 in the above conventional switch apparatus, a clearance between section 5B and section 6A causes little backlash in the rotation direction. This backlash is expanded at the tip ends of levers 3 and 4, causing a driver to feel uncomfortable rattle.